Mine wasn’t connecting very well on my iPhone 5. Some cords wouldn’t work at all. Some worked OK. Mostly it was getting that thing where the phone would rapidly toggle between charging and not charging.
I cleared some lint out of there at some point which made it better for a week maybe, but then back to normal and no more lint to be cleared.
I made a genius bar appointment at a local Apple store. They got me in right on the exact time the appointment was for. They tested it and found the exact same issue (that’s a first). They replaced the entire phone for free. I asked if that’s because I had Apple Care on it. Nope, they just do that for this issue. Plus I didn’t even have Apple Care on it.
The whole thing took 15 minutes. iCloud backup on WiFi maybe 30. Pretty damn sweet. This kind of thing will keep me on the Apple bandwagon.